Braking mechanism for sliding doors and the like



Nov. 6, 1956 N. R. GUILBERT, JR., Erm.. 2,769,196

BRAKING MECHANISM FOR SLIDING DOORS AND THE LIKE F'lled March 31. 1955 2 Sheets-Sheeni 1 WALTER B. K ELLE R M (Ittorneg NICHOLAS R. GUlL-B ERT, JR.

Nov. 6, 1956` N. R. GUILBERT, JR., ETAL 2,769,196

BRAKING MECHANISM FOR SLIDING DOORS AND THE LIKE Flled March 3l, 1953 2 Sheets-Sheet 2 I WwW/1 57 58 :Suventors NICHOLAS R. GUILBERT, JR.

Bg WALTER B. KELLER (Ittorneg Unit States Patent BRAKING MECHANISIVI FOR SLIDING DOORS AND THE LiKE Nicholas R. Guilbert, Jr., Chestnut Hill, and Walter B. Keller, Media, Pa., assignors to Guilbert, Incorporated, Philadelphia, Pa., a corporation of Pennsylvania Application March 31, 195i3, Serial No. 345,936

2 Claims. (Cl. lL-SS) This invention relates to braking mechanism for sliding doors and the like and is particularly suited to use with vertically sliding freight elevator doors of the type comprising upper and lower panels. These are usually mechanically operated `and as `they are opened they are often brought forcibly against stops limiting their travel. This causes undue wear and tear on the mechanism as a whole and objectionable noise and may also induce rebound of the door panel from its stops necessitating further attention by the operator to bring it to its proper position, that is with its upper edge bridging the gap between the building iloor and the oor of the elevator cab to facilitate passage of la wheeled vehicle or the like into or out of the latter.

Door arresting means have been provided for rapidly decelerating doors of this character just prior to their attaining the limits of their travel and contacting the stops, hydraulic cylinders, springs, and other mechanisms having been utilized for this purpose. None of these has been entirely satisfactory however, partly due to the necessity for readjusting them frequently to insure acceptable operation and none has gone into extended use.

It is therefore a principal object of our invention to provide improved braking means operative to impose frictionally a sharp deceleration on an elevator door or the like as it approaches the limit of its travel in the opening direction but offering substantially no resistance to the movement of the door in the opposite direction when it is to be closed.

A further object is to provide mechanism which when substantially duplicated in opposition on the sides of a dooror the like presents frictional surfaces adapted to engage suitable vanes or fittings attached to the door whereby the door itself through the medium of the vanes participates in effect in a wedging action setting up frictional resistance which induces its rapid deceleration in one direction, but offers little or no such resistance to door movement in the opposite direction.

A still further object is to provide frictional braking means of relatively simple character and comparatively low cost for rapidly decelerating substantially any object movable along a fixed path to and from a limit position through imposition of frictional resistance to its movement in one direction adjacent land at said limit but operative to withhold such resistance to its movement in the opposite direction away from said limit.

Other objects, purposes and advantages of the invention will hereinafter more fully appear or will be understood from the following description of certain embodiments of it illustrated in association with vertically sliding elevator doors in the accompanying drawings, in which:

Fig. l is a front elevation of one braking mechanism applied to the lower leaf or panel of a bi-parting elevator door.

Fig. 2 is a fragmentary enlarged front elevation-of a F lCe portion of the same structure showing the relation of the parts of the braking mechanism after the door has been brought to rest thereby.

Fig. 3 is a fragmentary detail corresponding to a portion of Fig. 2 but showing Ithe parts in a different relation as when the return movement of the door h-as been just initiated.

Fig. 4 is a horizontal section on line 4-4 in Fig. 2 in the direction of the arrow.

Fig. 5 is a fragmentary front elevation corresponding to Fig. 2 showing another embodiment of the invention; and

Fig. 6 is a horizontal section on line 6--6 in Fig. 5 in the direction of the arrow.

Referring now more particularly to Figs. 1 4 inclusive, mechanism embodying the invention is therein illustrated in operative association with an elevator door panel D arranged for vertical travel relatively to guides G secured to the wall W of an elevator hatchway or other xed portion of a building structure housing the elevator and including a floor, the broken line L (Fig. l) indicating the floor level to which the upper edge of the door (not shown) is brought to fully open the doorway, the guides G, preferably channel shaped or substantially U-shaped in cross section (Fig. 4), having one edge secured to the building wall adjacent the path of the door and the other embraced by suitable brackets on the door whereby the latter is confined in its movement to its proper rectilinear path. Doors of this character are usually provided with suitable wing irons (not shown) adapted to engage stops S and S fixed to wall W of the building structure to limit the descent of the door land thus hold the upper edge of the latter in alignment with oor level L.

It is in preventing the wing irons from violently contacting these stops by bringing them gently into contact therewith as the door reaches the limit of its travel that the braking mechanism of our invention is especially useful and it will iirst be described with particular reference to Figs. 2, 3 and 4 in connection with which it will be understood that the apparatus illustrated therein is substantially duplicated at the opposite side of the door (see Fig. l) to provide a wedging action or lateral counter-thrust which greatly enhances the eilicacy of the mechanism as a whole.

In this embodiment of the invention there are secured to opposite edges of door D for movement therewith substantially similar Vanes 1, l comprising metal plates or strips boltedy or otherwise adjustably attached to angle brackets 2 secured with the aid of bolts 3 to the door at a slight downwardly converging angle to the path of its travel, the lower ends of the vanes being oppositely inwardly bent to a somewhat wider angle to the vertical as indicated at 1a for a purpose which will hereinafter appear.

The mutually cooperative units for frictionally engaging the faces of vanes 1, 1 as the door approaches its lower limit position preferably are mounted adjacent the door guides G and the xed stops S, S; each includes an elongated substantially rectangular brake block 5 loosely supported from a plate 6 rigidly carried by one of the door guides G or other suitable support. This plate is provided adjacent its upper end with a bore 7 through which a bolt 8 Irigidly secured in the block passes with suicient clearance to permit limited relative movement between the block and the plate while the lower end of the block is loosely confined by a bolt 9 surrounded by a coil spring 10 which urges it outwardly from the plate, its travel in this direction being limited by the head of the bolt 9 when the brake is free of engagement by the door vanes.

Block 5 supports and is substantially embraced by a movable elongated. generally channel shaped brake shoe 11 comprising a friction facing 12 and provided with transverse pins 13, 14 passing through the block in slots 1S, 16 disposed at an angleY to its longitudinal center line to. permit limited. relative movement of the shoe as a whole at a corresponding. angle relatively to vthe block. At the other side of the path of the door at substantially the same level as theelements. just described a substantially similar block 5 is mounted in the same way as block 5y but in reverse, with. spring lil.' on bolt 9' urging it inwardly, and thus toward the block e in the same way the latter is urged. inwardly toward block 5 by its spring 9, the block S carrying a friction facing 12' duplicating the facing 12. on` block 5.

As previously indicated, dueto. the generally similar arrangement of parts adjacent the opposite door guides there is thus provided opposing friction facings 12, 12 having yielding mountings and respectively adapted to receive vanes 1, 1 carried by the door when the latter is depressed to engagement with them, the relieved surfaces rl facilitating entry of the vanes between the facings. As indicated in the drawings facings t2, 12 are disposed at slight upwardly divergent angles and suitably spaced apart for reception of the vanes which are correspondingly disposed at substantially complementary angularitywhereby on appropriate movement of the door, as for example downwardly in Fig. l, the vanes can enter between the facings, the vanes being preferably adjusted tov fully engage the shoes just before they attain substantial alignment therewith. Further motion of the door in opposition to the frictional resistance to it offered by the facings then swings blocks 5, 5 outwardly against the torce of springs 10, thereby progressively increasing that resistance until the door is brought to rest as the wing irons engage stops S, S', its rapid deceleration being relatively noiseless and of such nature as to inhibit rebound on engagement of the wing irons with the stops.

On the reverse movement of the door the frictional engagement between the facings and the vanes is initially retained but as each brake shoe 11 is free to slide upwardly relatively to block 5 to an extent limited by slots 1S, 16 each shoe therefore moves with the door and offers substantially no frictional resistance to such movement; the blocks under the influence of their springs 1t), 1d moreover move outwardly as pins 13, i4 move upwardly in the slots, as indicated in Fig. 3, until the blocks engage the heads of bolts 9, 9 which limit their movement in this direction. Further movement of the door, still frictionally carrying the shoes, causes pins 13, i4 to rise still further in slots 15, 16 but as the angularity of the latter retracts the frictional facings of the shoes from the door vanes the frictional drag of the vanes on the shoes is thereby broken as the door thereafter rises relatively free of the facings and brake shoes which may then return by gravity to their initial positions unrestrained by the vanes which by then have moved past them. It will be apparent that when the shoes are so constructed and arranged as to render uncertain their return to normal position by gravity as by thickening of lubricant supplied to its bearing surfaces from contamination or abnormally low temperatures, or in any event when the braking mechanism is used for a horizontally instead of a vertically moving door; a compression spring i7 or the like may be provided to insure it, a finger-like extension 18 on the plate 6 supporting a pin 19 to hold the spring in place, while the effects of gravity may of course be modied by making the angle of slots 15, 16 different from that indicated.

The embodiment of the invention just described is designed primarily for association with a vertical-ly sliding door and in this position gravity is usually effective without the aid of spring 17 to return the brake shoes to normal or inoperative position after the door vanes have moved out of engagement with their facings, but

it will be apparent that when the apparatus is used for decelerating a horizontally moving elevator door or the like the spring or equivalent means is generally required to insure such return.

It will further be understood that if desired a single brake shoe and but one vane cooperative with it may be employed, and the transverse thrust developed by the engagement of the vane with the brake shoe facing may then be resolved against the door guide at the opposite edge of the door instead of against the second brake shoe as. in the apparatus illustrated in Fig. 1 although when transverse thrust of each is resolved against the other excessive wear on the door guides is avoided and this arrangement is therefore usually to be preferred.

As a certain amount of adjustability in the apparatus is desirable to insure optimum operating conditions and to afford adequate provision for wear compensation we prefer to mount the vanes 1, 1 on their supporting brackets 2, 2 in such manner as t permit shims 2t) to be interposed between the vanes and the said brackets, countersunk bolts 21, carrying nuts 22 permitting ready removal of the vanes from thev brackets for the insertion or removal of such shims as may be requisite to insure accurate spacing of the vanes relatively to the friction facings on the brake shoes.

The embodiment of the invention illustrated in Figs. 5 and. 6 is similarly versatile and operates in accordance with the same principles as that just described; it is shown in simplified form and demonstrates a convenient reversal of the braking elements which may sometimes bev preferred. Thusit includes a somewhat eXible preferably spring steel braking vane S1 generally correspondingto vane 1 in Figs. 1 4 inclusive but carried by door D in this instance adjacent the outer extremity of its wing iron l, being. secured thereto. by an angle bracket 52 bolted tothe wing iron and to. which the vane is rigidly attached by bolts S3, 541 and nuts 55, 56, shims 57, 53- interposed between the vane and bracket providing suitable lateral adjustability for the former. The so-called wingY iron I is of usual construction consisting either of the laterally projecting end of a structural element of the door itself or a rigid metal plate secured to the door adjacent its upper edge and projecting outwardly beyond. its lateral edge. A chain hitch generally designated H may provide means for connecting to the wing iron a tension element (not shown) for counterbalancing the weight of the door or to provide for its mechanical operation.

The vane Si' extends below the bracket 52 and is substantially of the shape illustrated in Fig. 5 to afford a plane surface 59 for engagement with friction facing dil of a brake shoe 6i which in this instance is supported from the adjacent door guide G inwardly toward the door from vane 5l. Shoe di, like shoe i1 in Figs. 1 4 inclusive, is provided with angular slot and pin connections with its support, in this instance having slots 62, 63 receiving respectively pins ed, 65 projecting from a supporting bracket 66 which may be welded, bolted or otherwise secured to the wing iron stop Sa or other fixed part of the building structure.

The elements just described may be duplicated in reverse at the other side of the door in which arrangement the braking vanes which are here carried by the door embrace the brake shoes considered as a unit in a wedging action as the friction facings of the blocks tend to spread the vanes against the bias of their inherent spring tension when the door is opened to bring the vanes into engagement with the facings.

When the door after being brought to rest is moved in the opposite direction the brake shoes move with the vanes angulary inward until freed from engagement with them as the vanes are carried from the region of the shoes, and the latter then fall by gravity to their normal position preparatory to a succeeding braking operation. Obviously, as in the embodiment of the invention previously described, a spring or the like may be provided to insure their return if desired.

While we have .herein described certain embodiments of our invention with considerable particularlity as each may be utilized for braking a vertically sliding freight elevator door or the like it will be understood they as well as other embodiments thereof may be adapted to other siutations and for producing rapid deceleration of substantially any object moving on a predetermined path toward a fixed limit to bring it to rest quickly and smoothly substantially at said limit, .and that changes and modications in form, construction and arrangement of the parts other than those herein suggested will readily occur to those skilled in the art and may be madeif desired without departing from the spirit and scope o the invention as defined in the appended claims.

Having thus described our invention, we claim and desire to protect by Letters Patent of the United States: l. In braking apparatus for a reciprocally movable object, yielding means carried by the object providing spaced substantially flat surfaces converging in a plane parallel to the path of movement of the object in the direction away from one end of said path, arresting means disposed adjacent said path adapted for erigawgueL ment by said surfaces at the approach of the object to said end of its path including friction shoes respectively providing surfaces for such engagement whereby said yielding means will be exed outwardly and thereby retard the approach of the object toward said end of its path, and means supporting the shoes for movement with the object when it is moved away from its arrested position along paths converging in said plane at an angle greater than the angle of convergence of said substantially at surfaces.

2. Apparatus as defined in clairn 1 in which Ithe shoe supporting means include pin and slot connections v,be-

- tween each shoe and a fixed support and the major axes ofv the slots forming said connections extend angularly to the path of movement of the object.

. References Cited in the tile of this patent UNITED STATES PATENTS 797,767 Dyer Aug. 22, 1905 1,194,991 Gervais Aug. 15, 1916 1,256,297 Courson Feb. 12, 1918 1,807,113 Winans May 26, 1931 1,893,639 Stutson Jan. 10, 1933 1,948,640 Andrews Feb. 27, 1934 2,372,634 Breitenbach et al. Mar. 27, 1945 FOREIGN PATENTS 191,653 Great Brit-ain Jan. 18, 1923 

